Heat exchanger

ABSTRACT

A heat exchanger having a heat exchanger core having at least two rows of tube and fin blocks, each tube and fin block contains an assembly of tubes and fins, wherein the tubes are aligned parallel to each other while the fins are located between adjacent tubes, each tube having a first tube end and a second tube end, each tube and fin block of the first tube and fin block and the second tube and fin block having a manifold tube, the manifold tubes having a row of openings for a fluid tight connection with tubes of a tube and fin block, wherein the first tube ends of the first tube and fin block are fluid tight connected to the openings of a first manifold and the first tube ends of the second tube and fin block are fluid tight connected to the openings of a second manifold.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a heat exchanger, especially for a refrigeration cycle of a motor vehicle or for residential and/or commercial application.

Description of the Background Art

Two row heat exchangers are known in the prior art. Such two row heat exchangers are known as evaporators having two heat exchanger cores which are located in two rows and which are aligned in air flow direction one behind the other such that the air flow crosses first one of the two heat exchanger cores and then the other of the two heat exchanger cores.

It is known that the two heat exchanger cores are produced with two manifolds with a row of tubes and fins between the two manifolds such that each tube is inserted with one of his tube ends in an opening of one of the two manifolds and with the other tube end in an opening of the other manifold. Such heat exchanger cores are fluidically connected by connection tubes. Such a heat exchanger design requires four manifolds and the manufacturing process is costly.

Furthermore two row heat exchangers are known having only two manifolds, one manifold in each row of the heat exchanger while the two rows of heat exchanger cores having tubes and fins, the tubes are hairpin shaped having two tube ends which are each inserted in an opening of a manifold.

There are heat exchangers known which use hairpin shaped tubes which are bent before assembly of the heat exchanger. Such tubes and the fins between the tubes are difficult to assemble. Therefore, the assembly is costly. Furthermore, there are heat exchangers known which are assembled and brazed having straight tubes which are bent after brazing. These heat exchangers are easy to assemble and to braze but the bending process is difficult and might lead to leakage of tubes.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a heat exchanger having at least two rows of tube and fin blocks which is easy to assemble and manufacture while having a lower risk of leakages.

An exemplary embodiment of the invention relates to a heat exchanger, especially an evaporator, having a heat exchanger core having at least two rows of tube and fin blocks, a first tube and fin block and a second tube and fin block, each tube and fin block contains an assembly of tubes and fins, wherein the tubes are aligned parallel to each other while fins are located between adjacent tubes, each tube having a first tube end and a second tube end, each tube and fin block of the first tube and fin block and the second tube and fin block having a manifold tube, the manifold tubes having a row of openings for a fluid tight connection with tubes of a tube and fin block, wherein the first tube ends of the tubes of the first tube and fin block are fluid tight connected to the openings of a first manifold and the first tube ends of the tubes of the second tube and fin block are fluid tight connected to the openings of a second manifold, wherein the second tube ends of the tubes of the first tube and fin block and the second tube ends of the tubes of the second tube and fin block are fluid tight connected pairwise by means of a connecting element. Therefore, the heat exchanger can be produced and assembled without bending operations. Accordingly, the leakage rate of such heat exchangers is significantly reduced.

Each second tube end of the tubes of the first tube and fin block can be fluid tight connected to a second tube end of the tubes of the second tube and fin block by means of a connecting element. Therefore, there is a fluid connection between the tubes of the first tube and fin block and the tubes of the second tube and fin block.

The connecting element can be an arch shaped connecting element having at least one arch shaped fluid connecting channel or a plurality of arch shaped fluid connecting channels. With regard to the arch shaped fluid channels a fluid connector is provided using only a small volume reducing the total needed volume of the heat exchanger.

The connecting element provides a first inlet opening for a first second tube end and a second inlet opening for a second second tube end and the at least one fluid connecting channel or the plurality of fluid connecting channels for fluid connecting the first opening with the second opening, respectively for fluid connecting the first second tube end with the second second tube end. According to this design of the connecting element it is easy to assemble the connecting element with the respective second tube ends. Therefore, no bending operation of tubes is needed.

The connecting element provides a first cavity between the first inlet opening and the at least one fluid connecting channel or the plurality of fluid connecting channels and a second cavity between the second inlet opening and the at least one fluid connecting channel or the plurality of fluid connecting channels. The respective cavity provides a mixing of fluid from different channels leading to a more uniform temperature and pressure distribution of the fluid flowing through the tubes.

The connecting element can be made of a pair of plates which are located adjacent to each other and which are connected to each other providing the two openings and the at least on fluid connecting channel. Therefore, the connecting element can easily be made using two stacked plates.

The plates can have a profile forming the openings and the at least one fluid connecting channel or the fluid connecting channels. This design allows a cost-efficient production of the plates and of the connecting element, especially if the connecting element is made of a pair of plates.

The plates can be stamped metal plates. This allows a very efficient production leading to a cost-efficient product.

An assembly can be provided for assembling the two plates of a pair of plates as a pre-assembled unit. This allows a preassembly of the connecting element before brazing.

The assembly can be rivets, screws and/or tox elements. A tox element is a type of a rivet element which is in one piece formed out of at least one element to be connected. Therefore, a tox element allows a kind of riveting but without separate riveting elements.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1 is a perspective representation of a heat exchanger according to an exemplary embodiment;

FIG. 2 is a side view of the heat exchanger;

FIG. 3 is a top view of the heat exchanger;

FIG. 4 is a perspective representation of connecting element of the heat exchanger;

FIG. 5 is a schematic side view of one side of a plate of the connecting element of the heat exchanger; and

FIG. 6 is a schematic side view of the other side of the plate of the connecting element of the heat exchanger.

DETAILED DESCRIPTION

The FIGS. 1 to 3 show different views of an embodiment of a heat exchanger 1.

The heat exchanger 1 is in this shown embodiment a heat exchanger of a refrigerant cycle of the air-conditioning system of a motor vehicle or for residential and/or commercial application, e.g. for the use for residential or non-residential buildings etc. The heat exchanger may be e.g. an evaporator or a condenser.

Nevertheless the heat exchanger 1 might be another heat exchanger e.g. of a cooling cycle of a motor vehicle or of a residential or commercial application, like a heater core, a radiator or something different like an oil cooler or the like.

The heat exchanger 1 is a two-row heat exchanger having a heat exchanger core 2 having two rows 3, 4 of tube and fin blocks 5, 6.

A first tube and fin block 5 is provided and additionally a second tube and fin block 6 is provided which are arranged just adjacent to each other and which are approached by an air flow 7 one after the other. This means that the first tube and fin block 5 is approached by the air flow 7 first such that the air flows at first through the first tube and fin block 5 and after the air hast flown through the first tube and fin block the air flows through the second tube and fin block 6. The air flow 7 is schematically shown using the arrow marked with the reference numeral 7.

According to the invention the heat exchanger 1 has two or more rows 3, 4 and respectively two or more tube and fin blocks 5, 6. Therefore, the invention will be described as an example by way of the shown two-row embodiment but the invention is not limited to such two-row heat exchangers 1. The heat exchanger 1 may have a plurality of rows, for example three rows, four rows, five rows or more rows accordingly.

Each tube and fin block 5, 6 contains a plurality of tubes 8 and a plurality of fins 9. The tubes 8 and the fins 9 are arranged in an alternating fashion as a stack of tubes 8 and fins 9. On each end side of the tube and fin block 5, 6 side plates 10 may be provided.

The tubes 8 are aligned in parallel to each other while the tube ends 11, 12 are located adjacent to each other. The fins 9 are located between adjacent tubes 8. Each tube 8 has a first tube end 11 and a second tube end 12.

As can be seen from FIGS. 1 and 2 each tube and fin block 5, 6 of the first tube and fin block 5 and of the second tube and fin block 6 are having a manifold tube 22. The manifold tube 22 has openings 13 in which the tube ends 11, 12 of the tubes 8 are located and fluid tight connected. Therefore, the inside of the manifolds 22 is communicating with the fluid paths inside the tubes 8.

Each manifold 22 has a connector 14, 15, one of which is an inflow 14 and one of which is an inflow 15. The manifolds 22 are having an internal volume which are in this example not divided in sub-volumes. Therefore, the fluid enters at the inflow 14 in the first manifold 22, passes through the tubes 8 of the first tube and fin block 6 or 5, passes to the second tube and fin block 5 or 6 through the tubes 8 an enters the second manifold 22 and leaves the inflow 15.

Both manifolds 22 are made as a kind of manifold tubes 22 having a row of openings 13 for a fluid tight connection with tubes 8 of a tube and fin block 5, 6. Accordingly the first tube ends 11 of the tubes 8 of the first tube and fin block 5, 6 are fluid tight connected to the openings 13 of a first manifold 22 and the first tube ends 11 of the tubes 8 of the second tube and fin block 5, 6 are fluid tight connected to the openings 13 of a second manifold 22.

According to the invention the second tube ends 12 of the tubes 8 of the first tube and fin block 5, 6 and the second tube ends 12 of the tubes 8 of the second tube and fin block 5, 6 are fluid tight connected pairwise by means of a connecting element 16.

To allow a proper fluid flow each second tube end 12 of the tubes 8 of the first tube and fin block 5, 6 is fluid tight connected to a second tube end 12 of the tubes 8 of the second tube and fin block 5, 6 by means of a connecting element 16. Therefore, the tube ends 12 of one tube and fin block 5, 6 are each connected with on tube end 12 of the other tube and fin block 5, 6.

As can be seen in FIG. 3, the connecting element 16 is a basically arch shaped connecting element 16 having at least one arch shaped fluid connecting channel 17 or a plurality of arch shaped fluid connecting channels 17. These connecting channels 17 or this connecting channel 17 connects the tubes of the two connected tube and fin blocks 5, 6 to allow a fluid flow from one tube and fin block 5, 6 to the other tube and fin block 5, 6.

The connecting element 16 provides a first inlet opening 18 for a first of the second tube ends 12 and a second inlet opening 19 for a second of the second tube ends 12 and the at least one fluid connecting channel 17 or the plurality of fluid connecting channels 17 for fluid connecting the first opening 18 with the second opening 19, respectively for fluid connecting the first second tube end 12 with the second second tube end 12.

Furthermore, the connecting element 16 provides a first cavity 20 between the first inlet opening 18 and the at least one fluid connecting channel 17 or the plurality of fluid connecting channels 17 and it provides a second cavity 21 between the second inlet opening 19 and the at least one fluid connecting channel 17 or the plurality of fluid connecting channels 17. The cavities 21, 22 allow a mixture of the fluid leaving a tube 8 prior of entering the channels 17 and a mixture of the fluid leaving the channels 17 prior of entering the tube 8.

As can be seen in the FIGS. 4 to 6 the connecting element 16 is made of a pair of plates 23, 24 which are located adjacent to each other and which are connected to each other providing the two openings 18, 19 and the et least on fluid connecting channel 17.

The plates 23, 24 are having a profile forming the openings 18, 19 and the at least one fluid connecting channel 17 or the fluid connecting channels 17. The openings 23, 24 and the channels 17 are formed after two plates 23, 24 are connected to each other since each plate 23, 24 forms only half of the openings 23, 24 and the channels 17.

In a preferable embodiment the plates 23, 24 are made of stamped metal as stamped metal plates. Therefor the plates may be made of sheet aluminium which will be stamped to shape the plates 23, 24.

The connecting element 16 can be made by two plates 23, 24 using an assembly which are provided for the assembly of the two plates 23, 24 of a pair of plates 23, 24 in order to achieve a pre-assembled unit. This allows a pre-assembly of the connecting element before brazing of the heat exchanger 1.

According to an embodiment of the invention, the assembly may be rivets, screws and/or tox elements. This allows a quick and safe method of connection. The assembly might fit through the openings 25 in order to clamp the two plates 23, 24 together.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims. 

What is claimed is:
 1. A heat exchanger comprising: a heat exchanger core having at least two rows of tube and fin blocks, a first tube and fin block and a second tube and fin block, each tube and fin block contains an assembly of tubes and fins, wherein the tubes are aligned parallel to each other and the fins are located between adjacent tubes, each tube having a first tube end and a second tube end, each tube and fin block of the first tube and fin block and the second tube and fin block having a manifold tube, the manifold tubes having a row of openings for a fluid tight connection with tubes of a tube and fin block, wherein the first tube ends of the tubes of the first tube and fin block are fluid tight connected to the openings of a first manifold and the first tube ends of the tubes of the second tube and fin block are fluid tight connected to the openings of a second manifold; and a connecting element, wherein the second tube ends of the tubes of the first tube and fin block and the second tube ends of the tubes of the second tube and fin block are fluid tight connected pairwise via the connecting element.
 2. The heat exchanger according to claim 1, wherein each second tube end of the tubes of the first tube and fin block is fluid tight connected to a second tube end of the tubes of the second tube and fin block via the connecting element.
 3. The heat exchanger according to claim 1, wherein the connecting element is an arch shaped connecting element having at least one arch shaped fluid connecting channel or a plurality of arch shaped fluid connecting channels.
 4. The heat exchanger according to claim 3, wherein the connecting element provides a first inlet opening for a first-second tube end and a second inlet opening for a second-second tube end, and wherein the at least one fluid connecting channel or the plurality of fluid connecting channels for fluid connecting the first opening with the second opening, respectively for fluid connecting the first-second tube end with the second-second tube end.
 5. The heat exchanger according to claim 4, wherein the connecting element provides a first cavity between the first inlet opening and the at least one fluid connecting channel or the plurality of fluid connecting channels and a second cavity between the second inlet opening and the at least one fluid connecting channel or the plurality of fluid connecting channels.
 6. The heat exchanger according to claim 4, wherein the connecting element is made of a pair of plates that are located adjacent to each other and which are connected to each other providing the two openings and the at least on fluid connecting channel.
 7. The heat exchanger according to claim 6, wherein the plates have a profile forming the openings and the at least one fluid connecting channel or the fluid connecting channels.
 8. The heat exchanger according to claim 7, wherein the plates are stamped metal plates.
 9. The heat exchanger according to claim 6, wherein an assembly is provided for the assembly of the two plates of a pair of plates as a pre-assembled unit.
 10. The heat exchanger according to claim 9, wherein the assembly is rivets, screws and/or tox elements.
 11. The heat exchanger according to claim 1, wherein the heat exchanger is an evaporator. 